Mora believed middle linebacker would be a position of great depth before losing rookie third-round pick Jordan Beck for the year before the season opener and then losing the team's biggest free-agent addition, Ed Hartwell, to a torn Achilles' tendon in Week 5.

Hartwell's injury triggered a chain reaction of moves that made Boley a starter while Keith Brooking moved inside from outside linebacker.

Babineaux had to move up at end when right end Brady Smith broke his right big toe; he's missed the last five games. The Falcons have held off placing Smith on injured reserve. Smith acknowledged this week he does not know when he will return.

"It's been horrible," Smith said. "The worst for me personally is to not be able to go out there and contribute at all. I know I can help. I know there are things I can go to contribute, but I feel like my hands have been tied and I can't do anything about it."

Two more rookies - Chauncey Davis and Darrell Shropshire - are top backups on the line.

Other changes which have the Falcons looking younger on offense were less traumatic. The team's last two first-round draft picks, receivers Michael Jenkins and Roddy White, have taken starting jobs from Peerless Price, who was cut in the preseason, and Dez White, who was placed on injured reserve last week.

But the changes on defense are of the greatest concern to Mora and his staff.

Mora says a startling number of injuries have hit his team at the same positions: defensive end, linebacker and nickel back.

"We just have to keep developing these kids that are playing for us," Mora said. "You can't make an excuse. ... We have to keep developing Babineaux. Babs is playing defensive end and we brought him here to play the backup three-technique (tackle). That's what it is. So we have to develop him."

Mora said Shropshire, an undrafted free agent, was projected to be a practice squad player. "Now he's playing for us," Mora said. "We have to play him."

Boley, meanwhile, was expected to play on special teams, much like Demorrio Williams in his 2004 rookie season. Williams now is the other starting outside linebacker. Boley was projected as a future starter, but not this year.

"We have to develop him," Mora said. "It's not easy. We can't cry about it, we just have to develop them the best we can."

The latest addition to the injury list came last week when Rossum, the return specialist and nickel back, hurt his knee. Rossum's replacement at nickel back, Leigh Torrence, was on the team's injury report early in the week, but was cleared Friday.

Saints coach Jim Haslett said last week he could see the Falcons were unsettled at linebacker when Atlanta took a 34-31 win over his team in San Antonio on Oct. 16. That was the first game after Hartwell's injury forced a reshuffling of the linebackers.

As the Falcons struggled to adjust to the changes, the Saints rushed for 211 yards, still the most allowed by Atlanta this season.

Haslett says he can see the linebackers now are playing with more confidence.

"They are so settled in more at the linebacker spot," Haslett said. "They have great speed at linebacker and great speed on the back end, so they are settled into what they are doing now. They are settled in personnel wise."

Mora said Brooking played his best game of the season - and perhaps one of the best games of his career - last week, but the performance was lost in the Falcons' loss to Carolina.

Now Mora has to hope young players Boley and Babineaux can catch up with Brooking, Patrick Kerney, Rod Coleman and other veterans.

"You don't have the years of experience to draw from when something happens quickly," Mora said. "I think with each rep these guys take, because they're well-coached and because they're talented guys who work hard, they're getting better and better.

"I get excited about the progress that Boley, Shropshire, Babineaux and Davis are making. It's good to see. Now we just need to get all 11 on every play doing it right for 60 plays in a row. That's the challenge."